title: Escherichia albertii and Hafnia alvei are candidate enteric pathogens with divergent effects on intercellular tight junctions.
abstract: Attaching-effacing lesion-inducing Escherichia albertii and the related, but non-attaching-effacing organism, Hafnia alvei, are both implicated as enteric pathogens in humans. However, effects of these bacteria on epithelial cells are not well-characterized. Related enteropathogens, including enterohemorrhagic Escherichia coli O157:H7, decrease epithelial barrier function by disrupting intercellular tight junctions in polarized epithelia. Therefore, this study assessed epithelial barrier function and tight junction protein distribution in polarized epithelia following bacterial infections. Polarized epithelial (MDCK-I and T84) cells grown on filter supports were infected apically with E. coli O157:H7, E. albertii, and H. alvei for 16h at 37 degrees C. All strains decreased transepithelial electrical resistance and increased permeability to a dextran probe in a host cell-dependent manner. Immunofluorescence microscopy showed that both E. coli O157:H7 and E. albertii, but not H. alvei, caused a redistribution of the tight junction protein zona occludens-1. In contrast to E. coli O157:H7, E. albertii and H. alvei did not redistribute claudin-1. Western blotting of whole cell protein extracts demonstrated that each bacterium caused differential changes in tight junction protein expression, dependent on the host cell. These findings demonstrate that E. albertii and H. alvei are candidate enteric pathogens that have both strain-specific and host epithelial cell-dependent effects.
authors.affiliation: Cell Biology Program, Research Institute, Hospital for Sick Children, University of Toronto, Room 8409, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Donato
authors.forename: Mehri
authors.initials: M
authors.lastname: Zareie
authors.forename: Agatha N
authors.initials: AN
authors.lastname: Jassem
authors.forename: Narveen
authors.initials: N
authors.lastname: Jandu
authors.forename: Nelab
authors.initials: N
authors.lastname: Alingary
authors.forename: Soo Chan
authors.initials: SC
authors.lastname: Carusone
authors.forename: Kathene C
authors.initials: KC
authors.lastname: Johnson-Henry
authors.forename: Philip M
authors.initials: PM
authors.lastname: Sherman
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002460:Cell Line; D002463:Cell Membrane Permeability; D062445:Claudin-1; D004285:Dogs; D004756:Enterobacteriaceae Infections / Q000378:metabolism / Q000382:microbiology*; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology; D004925:Escherichia / Q000472:pathogenicity* / Q000502:physiology; D019453:Escherichia coli O157 / Q000472:pathogenicity; D020611:Hafnia alvei / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000382:microbiology*; D008565:Membrane Proteins / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism / Q000382:microbiology*
chemical_list: C568108:CLDN1 protein, human; D062445:Claudin-1; D008565:Membrane Proteins